A power transformer having its main high-power windings encapsulated in a cast body of epoxy resin is filled with a dielectric cooling liquid having a boiling point slightly above the normal full load operating temperature of the cast coil assembly. To enhance cooling of the coil by the ambient liquid heat-conducting pins embedded in the windings extend to the outer surface of the coil assembly and have exposed surface areas sufficiently small to exceed the vaporization temperature of the liquid. Consequently bubbling from these boiling sites enhances heat transfer over substantially the entire coil surface.
A cooling apparatus for machinery utilizing a vaporizable liquid refrigerant and constituted by a tank in which machinery to be cooled is immersed in the vaporizable liquid refrigerant sealed within the tank, a condensor disposed above the tank substantially horizontally, and distributing pipes connecting the tank with the condensor so as to convey the vapor produced from the vaporizable liquid refrigerant within the tank by the heat generated in the machinery to the condenser, and the vapor is condensed in the condenser, returning to the tank again through passages separately constituted in the distributing pipes.
A semiconductor device is immersed into a cooling medium in its liquid phase disposed in a vessel. The cooling medium changes to its vapor phase due to heat from the semiconductor device to enter a condenser located above the vessel. The cooling medium condensed in the condenser passes through a conduit connected to the lower portion of the vessel to be directly mixed with the liquid cooling medium within the vessel.
A transformer assembly comprises a tank body enclosing a transformer and a cooling liquid. A cooling collar is fixedly attached to the outer surface of the tank body. The cooling collar is formed separately from the tank body in a corrugated shape so as to be elastically expandably mounted onto the tank body. The collar is attached to the tank body by a thermally conductive epoxy. The corrugations of the collar define cooling fins for dissipating heat from the tank body. The cooling collar can be of one-piece or multi-piece construction, the latter comprising a plurality of collar segments hooked together in end-to-end fashion.
A flywheel power source having a flywheel supported by a bearing system for rotation inside an evacuated container. A brushless motor and generator is coupled to the flywheel for accelerating and decelerating the flywheel for storing and retrieving energy. The generator has a rotor coupled to the flywheel, and a stationary stator wound using multiple-strand individually insulated conductor wire coils. A heat energy transfer system passively cools the stator by heat transfer from the stator to an unpumped liquid coolant surrounding the coils and in intimate contact with the conductors in the coils. The stator is mounted in a stator coolant vessel that is partially filled with the coolant. The liquid coolant limits the maximum temperature of the coils during discharging of the flywheel power source.
An electrical apparatus, such as a distribution transformer, having heat pipe cooling. The transformer is provided with a cover in the form of a heat pipe with an evaporator section extending from the cover into the dielectric fluid of the transformer. The top of the cover forms the condenser section of the heat pipe.
